102,910 research outputs found
Study of alpha-synuclein fibrillation: State of the art and expectations
No full textSince the discovery of the presence of fibrillary forms of α-synuclein (α-syn) in Lewy bodies (LB) and Lewy neurites in the brain of patients affected by Parkinson’s disease (PD) and dementia with LB, great effort has been dedicated to study the features of α-syn fibrillation. In parallel, the pathological relevance of the different toxic forms of α-syn has been also matter of investigation. In the last twenty years, scientists have been able to single out that α-syn fibrillation initiates pathological mechanisms that by contributing to or triggering neurodegeneration/neuroinflammation, may lead to PD pathogenesis. This notwithstanding, we still ignore the reasons why α-syn shifts from its natively unfolded conformation to toxic oligomeric and fibrillary forms. The chameleonic nature of monomeric α-syn, and the extremely polymorphic characteristics of aggregated strains, renders it difficult to picture the real nature of α-syn fibrils, their exact composition and formation dynamics. Recently, sophisticated biophysical methods and microscopy techniques have been exploited to study α-syn fibrillation. Here, we provide an overview of the most relevant advancement in our understanding of α-syn fibrils formation and conformation. Nonetheless, numerous techniques and patient- derived experimental models still need to be optimized to actively disclose causes and characteristics of α-syn fibrillation in disease-specific cellular milieux
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No full textIn vitro fermentation of feed ingredients by fresh or frozen pig fecal inocula
No full textIn vitro techniques can offer a rapid, repeatable and cost-effective alternative to in vivo experiments. We investigated the gas production (GP) of nine different feeds commonly used in Italian and Maltese pig farms in order to assess the use of the Ankom system in this species and to compare the in vitro microbial activity fresh or frozen inocula derived from piglet feces. Proximate and polyphenolic analyses were determined for all substrates. Fermentation profiles were measured according to the cumulative GP technique. Analysis of GP values revealed significant differences in the fermentation patterns mainly due to substrate and inoculum effects. Fermentation parameters varied significantly according to the substrate ingredients. The frozen inoculum generally led to more total GP than for fresh, with the exception of hard wheat bran pellets (HWBP), pelleted pulp and mature carob. Conversely the fresh fecal inoculum had an earlier maximum time to reach maximum GP than the frozen, showing a higher maximum rate of GP in all substrates excepting for HWBP. A significant difference in frozen and fresh inocula was found for the complete formulation. Further studies are required to confirm the variation between fresh and frozen fecal inocula to a wider range of feed, including those that could have negative biological effects
Kit Radicaux Libres, a new innovative biological application for monitoring oxidative stress in pigs
No full textKit Radicaux Libres (KRL) test is a biological application, successfully applied on humans, helpful for the study of the total antiradical activity. In the present work, the first objective was to test on a subset of pig blood samples in order to determine the maximum time of storage able to provide reliable results. Blood samples were collected from 46 piglets and determinations were carried out on the blood samples after three h from collection (T1) and thereafter at 24 (T2) and 48 (T3) h. Successively blood samples from 313 piglets (171 castrated males and 142 females) were collected and analysed in order to determine reference intervals. Results are expressed as half-haemolysis time (HT50 in min), that is a reference point for blood susceptibility to free radical attack. Our findings showed that for samples analysed at T1 and T2 there were no significant changes but significantly increased values (P<0.05) were obtained when samples were analysed after 48 h from collection, underlining biological and analytical interference due to the hemolysis of the samples. The reference values found in the subjects, expressed as ET AL50 were 46.6-68.7 min (males) and 52.5-86.8 min (females) in RBC, 59.8-93.6 min (males) and 70.5-113.0 (females) in whole blood. In conclusion, a prolonged time (till +48 h) caused haemolysis, therefore the use of freshly collected blood is strictly recommended. The reference values obtained are considered to represent valid reference ranges for healthy pigs starting after weaning to 175 days of age under modern husbandry conditions
Implant Periapical Lesion: Clinical and Histological Analysis of Two Case Reports Carried Out with Two Different Approaches
No full textPeriapical implantitis (IPL) is an increasingly frequent complication of dental implants. The causes of this condition are not yet entirely clear, although a bacterial component is certainly part of the etiology. In this case series study, two approaches will be described: because of persistent IPL symptoms, a patient had the implant removed and underwent histological analysis after week 6 from implantation. The histomorphometric examination revealed a 35% bone-implant contact area involving the coronal two-thirds of the implant. The apical portion of the fixture on the other hand was affected by an inflammatory process detectable on radiography as a radiolucent area. The presence of a probable root fragment, detectable as an imprecise radiopaque mass in the zone where the implant was later placed, confirms the probable bacterial etiology of this case of IPL. On the other hand, in case number 2, the presence of IPL around the fixture was solved by surgically removing the implant apical third as well as the adjacent tooth apex. It may be concluded from our histological examination that removal of the apical portion of the fixture should be considered an effective treatment for IPL since the remaining implant segment remains optimally osseointegrated and capable of continuing its function as a prosthetic abutment. Careful attention, however, is required at the implantation planning stage to identify in advance any sources of infection in the edentulous area of interest which might compromise the final outcome
Faecal steroid analysis in two captive female cheetahs
No full textIntroduction and aim. Cheetahs (Acinonyx jubatus), as most wild felid species, is an induced
ovulator and reproduces poorly in captivity, a problem attributed to inappropriate husbandry (1).
Monitoring endocrine activity is essential for assessing the reproductive potential, but hormonal
determination trough blood serum sampling is an unpractical procedure in these species, as it
requires anaesthesia and restraint. It has been demonstrated in the domestic cat that estrogens and
progesterone are secreted into faeces (1,2) and some Authors already applied this method to other
wild felids (1,3,4), as well as to cheetahs (5,6). However, cheetah management, i.e. social groups
and caging situations, was not standardized throughout the period of the study or a low number of
samples were collected during short time periods. The aim of the present work was to evaluate the
dynamic of faecal estrogens and progesterone throughout an entire year in two cheetahs constantly
housed with conspecific males in the Northern of Italy.
Materials and methods. Two female cheetahs (Geijsha and Duchessa, 2 years of age) maintained
at Le Cornelle Animal Park (Valbrembo, BG, Italy) and housed with 3 conspecific males were
included in this study. Faecal samples were collected daily for one year (from August 2007 to July
2008) and immediately frozen and stored at -20°C. Faecal oestradiol (E2) and progesterone (P4)
metabolites were extracted from fresh samples as previously described in dry samples (1). The
metabolites were quantified using radioimmunoassay. Basal E2 and P4 values and the duration of
the estrous cycle on the whole sampling period were calculated according to the method proposed
by Brown et al., 1996 (6). Data are resumed as mean ±SD.
Results. Faecal E2 basal values were 21.6+5.8 ng/g and 19.3+5.1 ng/g with peak concentrations
ranging from 30.6 to 73.8 ng/g and from 29.6 to 164.8 in Geijsha and Duchessa, respectively.
Estrous cycle duration was 10.4±3 (n=13, range, 6-15 days) and 11.3 ± 6.9 days (n=10, range, 5-23
days) in the two females. The males did not show any interest in the females which did not display
evident behavioural signs of estrus throughout the year. Faecal P4 basal values of 112.6+41.5 ng/g
and 100.6+23.4 ng/g remained at baseline values all year. In addition, none of the female were
continuously cyclic: follicular activity was interrupted by anestrous periods of 1 to 4 months in
duration and not associated with season.
Conclusions. These data suggest that captive cheethas show a discontinuos ovarian ciclicity which
duration and anestrus periods are similar to those described in the literature (6) in which estrous
cycle duration from 10.4±1 to 19±2.2 days and anestrous periods of 2 to 5 months are reported. In
the present study extraction of steroid metabolites was performed from fresh faecal sample, thus a
comparison with hormonal concentrations in dry samples reported by other authors is not possible.
It is generally accepted that behavioural signs of estrous are difficult to interpret in cheetahs,
however lack of mating and of subsequent luteal phase were likely due to the continous presence of
males which sexual interest was inhibited. Thus, adequacy of husbandry conditions is necessary and
enforced social living should be avoided in order to increase reproductive activity of captive
cheethas.
Aknowledgements. We thank E. Benedetti, N. Benedetti and Dr. R. Schneider of Le Cornelle
Animal Park for logistical support and sample collection. This study was supported by PUR 2008.
References. 1) Brown et al., Biol Reprod 1994;51:776-86; 2) Shille et al., Zoo Biol 1984;3:201-09;
3) Brown et al., J Reprod Fertil 2001;Suppl 57:71-82; 4) Graham et al., Zoo Biol 1995;14:233-37;
5) Czekala et al., Zoo Biol 1994;13: 119-28; 6) Brown et al., J Reprod Fertil 1996;106:337-46
Replacement effect of dietary vitamin E with different source of polyphenols on growth performance and vitamin E status in post-weaning piglets
No full textVitamin E has a vital role as an antioxidant and immunomodulator in animal species. Dietary supplementation with high levels of vitamin E is usually recommended in post-weaning piglets, when they show a decline in serum vitamin E concentration, reduced growth rate and susceptibility to stress. However, due to its synthetic nature and uneven distribution in tissues, the researchers continuously search for cost effective natural alternatives, and polyphenols, due to their antioxidant properties, could be such an alternative.
Therefore, the present study aims to investigate the partial replacement effect of vitamin E as suggested from additive company and literature in broiler with different sources of polyphenols on growth performance and serum vitamin E concentration in piglets.
Piglets (n = 350, body weight (BW) 7.20 kg), balanced for sex and BW were randomly assigned to seven experimental dietary groups: CON- (401 mg/kg vit E); CON+(175.8 mg/kg vit E); groups C, D, E, F and G containing each one 87.9 mg/kg vitamin E + products C (citrus and tannins) D (grape pip soluble), E (dry grape extract and carrier), F (freeze-dried melon juice and flesh, palm oil and microcrystalline cellulose), G (onion soluble and grape soluble) vitamin E equivalent, respectively. The trial lasted 35 days. Individual piglet weights at day 0 (d0) and day 35 (d35) and pen feed consumption were recorded for calculation of average daily gain (ADG) and feed conversion ratio (FCR). Blood samples were collected on d0 and d35 to determine serum vitamin E concentration.
Results showed that after 35 days of differentiated feeding, C group consumed less feed probably due to a taste not appreciated by piglets, exhibiting a lower (p<0.05) final body weight (15.04 kg) with a lower (p<0.05) ADG (0.223 kg) and worse FCR (2.1 kg/kg) compared to all other groups showing overlapping growth performances. No mortality was registered throughout the entire period. No effect of sex was found. Serum vitamin E concentration showed a general increase in all groups at d35 (p<0.001) and no effect of diet was detected; no clinical sign of vitamin E deficiency was noted in any piglet. In conclusion, the partial replacement of vitamin E with polyphenols results in unchanged growth performance among groups, excepting C group; considering vitamin E serum concentration, all integrations seem to be potentially reliable. Anyway, further research is needed to determine the effects also on other physiological indicators
Somministrazione di PGF2α dopo il parto nella bovina da latte : effetti sulla concentrazione ematica di idrossiprolina
No full textHow type of parturition and health status influence hormonal and metabolic profiles in newborn foals.
No full textThyroid hormones, insulin growth factor I (IGF-I) and non-esterified fatty acids (NEFA) represent important hormonal and
metabolic factors associated with perinatal growth and maturation. Their action could be influenced by the type of parturition and
the health status of the foal and therefore the aim of this work is to evaluate their plasma concentrations in newborn foals during
the first 2 wks of life. Three groups of subjects were enrolled: 15 healthy foals born by spontaneous parturition, 24 healthy foals
born by induced parturition and 26 pathologic foals. From each of the healthy foals, blood was collected at 10, 20 and 30 minutes,
3 and 12 hours from birth, daily from Day 1 to Day 7, and at Day 10 and 14 of life. In pathologic foals samples were collected
twice a day from the day of admission at the hospital until the day of discharge or death. Thyroid hormones (T3 and T4) and IGF-I
were analyzed by radioimmunoassay and NEFA by enzymatic-colorimetric methods. In all the three groups a declining trend of
T3 and T4 plasma concentrations was detectable, with lower levels in the pathologic group compared to healthy foals.
Spontaneous foals showed higher levels of T3 at 7 d compared to induced foals, while T4 levels were higher in spontaneous vs.
induced foals before 6 h of life, at three and seven days. IGF-I showed increasing plasma concentrations in all three considered
groups. No differences were found between healthy and pathologic foals. NEFA in spontaneous and induced healthy foals showed
a declining trend with higher levels during the first hours of life. Pathologic foals presented higher levels compared to spontaneous
foals only at 24 h and 10 d. These data suggest that the type of foaling could influence the reference ranges for thyroid hormones.
Moreover, pathologic foals showed some hormonal and metabolic differences related to their health status. Above all changes of
thyroid hormones levels, early in postnatal life, could be a cause, and not only a consequence, of the diseased condition of these
foals
Estrogen replacement therapy in a man with congenital aromatase deficiency: Effects of different doses of transdermal estradiol on bone mineral density and hormonal parameters
No full textThe effects of different doses of transdermal estradiol (TE) on bone mineral density (BMD) in a man with aromatase deficiency were evaluated. The study protocol was divided in the following four phases: phase 1, before estradiol treatment; phase 2, 50 mu g TE twice weekly for 6 months; phase 3, 25 mu g TE twice weekly for 9 months; and phase 4, 12.5 mu g TE twice weekly for 9 months. X-rays of hands, legs, and pelvis were performed, and BMD of the lumbar spine, hormonal parameters (LH, FSH, testosterone, and estradiol), and markers of bone turnover were determined during each phase. BMD in phase 1 was 0.933 g/cm(2) and increased to 1.051 and 1.173 g/cm(2) after 4 and 7 months of TE, respectively. In phase 3, BMD reached the maximum value (1.275 g/cm(2)). In phase 4, BMD decreased to 1.180 g/cm(2) and was 1.029 g/cm(2) at the end of the study protocol. A bilateral necrosis of femoral heads was also detected by x-ray films. In phase 1 serum testosterone was in the normal range, whereas serum estradiol was undetectable. During the 24-month period of treatment with TE (phases 2-4), estradiol was directly related to the amount of TE, whereas LH was inversely related to estradiol serum levels. Estradiol and gonadotropins reached optimal values only in phase 3, when FSH also was near normal; serum testosterone concentrations were normal in phases 3 and 4. This study confirms the role of estrogens in achieving and maintaining bone mineral content in the human male, providing further clinical tools useful in the management of bone loss in aromatase deficiency in the male, We suggest that the adequate substitutive dose of TE for maintaining both bone mass and normal estradiol serum levels in adult men with aromatase deficiency may be 25 mu g twice weekly (0.47 mu g/kg weekly)
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